net/mlx4_en: Add Low Latency Socket (LLS) support

[cascardo/linux.git] / drivers / net / ethernet / mellanox / mlx4 / en_netdev.c

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index ade276c..ab9ec91 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -38,6 +38,7 @@
 #include <linux/slab.h>
 #include <linux/hash.h>
 #include <net/ip.h>
+#include <net/ll_poll.h>
 
 #include <linux/mlx4/driver.h>
 #include <linux/mlx4/device.h>
@@ -67,6 +68,30 @@ int mlx4_en_setup_tc(struct net_device *dev, u8 up)
        return 0;
 }
 
+#ifdef CONFIG_NET_LL_RX_POLL
+/* must be called with local_bh_disable()d */
+static int mlx4_en_low_latency_recv(struct napi_struct *napi)
+{
+       struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
+       struct net_device *dev = cq->dev;
+       struct mlx4_en_priv *priv = netdev_priv(dev);
+       struct mlx4_en_rx_ring *rx_ring = &priv->rx_ring[cq->ring];
+       int done;
+
+       if (!priv->port_up)
+               return LL_FLUSH_FAILED;
+
+       if (!mlx4_en_cq_lock_poll(cq))
+               return LL_FLUSH_BUSY;
+
+       done = mlx4_en_process_rx_cq(dev, cq, 4);
+
+       mlx4_en_cq_unlock_poll(cq);
+
+       return done;
+}
+#endif /* CONFIG_NET_LL_RX_POLL */
+
 #ifdef CONFIG_RFS_ACCEL
 
 struct mlx4_en_filter {
@@ -1445,6 +1470,8 @@ int mlx4_en_start_port(struct net_device *dev)
        for (i = 0; i < priv->rx_ring_num; i++) {
                cq = &priv->rx_cq[i];
 
+               mlx4_en_cq_init_lock(cq);
+
                err = mlx4_en_activate_cq(priv, cq, i);
                if (err) {
                        en_err(priv, "Failed activating Rx CQ\n");
@@ -1694,10 +1721,19 @@ void mlx4_en_stop_port(struct net_device *dev, int detach)
 
        /* Free RX Rings */
        for (i = 0; i < priv->rx_ring_num; i++) {
+               struct mlx4_en_cq *cq = &priv->rx_cq[i];
+
+               local_bh_disable();
+               while (!mlx4_en_cq_lock_napi(cq)) {
+                       pr_info("CQ %d locked\n", i);
+                       mdelay(1);
+               }
+               local_bh_enable();
+
                mlx4_en_deactivate_rx_ring(priv, &priv->rx_ring[i]);
-               while (test_bit(NAPI_STATE_SCHED, &priv->rx_cq[i].napi.state))
+               while (test_bit(NAPI_STATE_SCHED, &cq->napi.state))
                        msleep(1);
-               mlx4_en_deactivate_cq(priv, &priv->rx_cq[i]);
+               mlx4_en_deactivate_cq(priv, cq);
        }
 
        /* close port*/
@@ -2090,6 +2126,9 @@ static const struct net_device_ops mlx4_netdev_ops = {
 #ifdef CONFIG_RFS_ACCEL
        .ndo_rx_flow_steer      = mlx4_en_filter_rfs,
 #endif
+#ifdef CONFIG_NET_LL_RX_POLL
+       .ndo_ll_poll            = mlx4_en_low_latency_recv,
+#endif
 };
 
 static const struct net_device_ops mlx4_netdev_ops_master = {